Connector lock mechanism

ABSTRACT

A connector lock mechanism which not only can reduce the number of parts required in male and female connectors to be engaged with each other and the number of assembling steps of the connectors but also can surely detect a partially engaged condition between the male and female connectors. In a connector lock mechanism ( 31 ), there is included a connector removing mechanism ( 48 ) which is composed of a flexible elastic piece ( 35 ) formed integrally with one connector or male connector ( 32 ), and a push-out guide surface ( 41 ) formed integrally with the other connector or female connector ( 33 ) and capable of deforming the flexible elastic piece ( 35 ) elastically to thereby generate a push-out force pushing back the two connectors in their mutually removing directions. And, the elasticity of the flexible elastic piece ( 35 ) and the inclination angle of the push-out guide surface ( 41 ) are set such that the push-out force to be generated by the connector removing mechanism ( 48 ) is larger than mutual contact resistance caused by and between male- and female-type terminals respectively stored within their associated connectors.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a connector lock mechanism which, whena set of male and female connectors are engaged with each other, if thelength of the mutual engagement of the two connectors reaches a presetlength, locks the mutually connected condition of the male and femaleconnectors and, in particular, to an improved connector lock mechanismwhich is capable of detecting the incomplete engagement (halfengagement) between the male and female connectors.

2. Description of the Related Art

Conventionally, when a plurality of electrical wires are electricallyconnected together or circuit boards equipped in various equipment areelectrically connected to electrical wires, generally, there has beenwidely used a system in which such connection can be achieved by meansof mutual engagement between a set of male and female connectors. Thatis, if a set of male and female connectors respectively formed ofinsulating resin or the like are engaged with each other, then male- andfemale-type terminals respectively stored within the female and maleconnectors are engaged with each other to thereby complete the mutualelectrical connection between the male and female connectors. On theother hand, if the mutual engagement between the male and femaleconnectors is removed, that is, if the two connectors are separated fromeach other, then the electrical connection between the male- andfemale-type terminals is likewise removed.

Therefore, the male and female connectors include a connector lockmechanism which is able to lock the two connectors in a well connectedcondition, that is, in such a manner that it can prevent inadvertentdisengagement between the male and female connectors due to vibrationsapplied thereto under the connector operating environment.

An example of the conventional connector lock mechanisms is disclosed inJapanese Utility Model Publication No. 1-98484 of Heisei and the like.In particular, in the conventional connector lock mechanism, there areemployed a set of male and female connectors 1 and 2 which are shown inFIG. 28. One connector 1 includes a pair of flexible arms 11 and 12,which respectively extend along the direction of arrow M in which oneconnector 1 can be engaged with the other connector, and two engagingportions 13 which are respectively formed on their associated flexiblearms 11 and 12 in such a manner as to project therefrom. Also, the otherconnector 2 includes a pair of arm guide surfaces 21 and 22 which arecapable of flexing their associated flexible arms 11 and 12 until thelength of the mutual engagement between the two connectors reaches apreset length (i.e., when the two connectors are fully engaged), and twosecuring means 23 which, when the mutual engagement length reaches thepreset length, can secure their associated engaging portions 13 tothereby prevent the two connectors from being removed from each other.

The two flexible arms 11 and 12 are disposed on the upper surfaceportion of one connector 1 in such a manner that they are spaced fromeach other in the lateral direction and are arranged parallel to eachother. Also, the two engaging portions 13 respectively includeprojections which project outwardly in the lateral direction from therespective leading end portions of the two flexible arms 11 and 12.

Further, the two arm guide surfaces 21 and 22 of the other connector 2are respectively formed on the two sides of the upper surface portion ofthe connector 2 in such a manner that their associated engaging portions13 can be contacted therewith when the two connectors 1 and 2 areoperated for their mutual engagement. The arm guide surfaces 21 and 22are also formed as tapered surfaces which are able to flex theirassociated flexible arms 11 and 12 inwardly in the lateral direction asthe mutual engagement between the two connectors progresses.

Moreover, the securing means 23 includes cavities which are respectivelyformed in front of the arm guide surfaces 21 and 22 in such a mannerthat their associated engaging portions 13 can be fitted into thesecuring means 23. If the connector mutual engagement advances, thenmale- and female-type terminals (not shown) respectively stored withinthe respective connectors start to be connected together. Upon furtheradvancement the engaging portions 13 of one connector 1 are respectivelyengaged with the securing means 23 of the other connector 2. Thus, themale- and female-type terminals stored within their respectiveconnectors are connected together electrically in a necessary andsufficient contact condition.

When the engaging portions 13 of one connector 1 are respectivelyengaged with the securing means 23 of the other connector 2, theinwardly flexed conditions of the respective flexible arms 11 and 12 arereturned back to their original conditions. A key 24 is then insertedbetween the engaging portions 13 and 13 to prevent the two flexible arms11 and 12 from being flexed again. Thus, the connectors are locked in amutual engagement condition.

To remove such locked condition, the key 24 may be pressed down to aretreat space 25 formed below the key 24, so that it is no longerbetween the pair of engaging portions 13 and 13. After the lockedcondition of the flexible arms 11 and 12 is removed, if the twoconnectors 1 and 2 are pulled apart, then the connectors can bedisengaged.

The pressing force necessary to bring the two connectors 1 and 2 intomutual engagement in the above-mentioned manner varies depending on thedimensional errors of the connectors 1, 2, and the dimensional errors ofthe male- and female-type terminals stored within their respectiveconnectors. For example, as shown in FIG. 29, even if the engagingoperation is executed with a given pressing force, there can occur anoperation mistake or a wrong operation; that is, the engaging operationcan be ended in a partially engaged condition in which the engagingportions 13 of the flexible arms 11 and 12 do not arrive at theirassociated securing means 23 but they remain in the flat portions 21 aand 22 a of the arm guide surfaces 21 and 22 which are located beforethe securing means 23.

If the connectors are used in such incomplete or partially engagedcondition, for example, in a wire harness connector which is used in anautomobile, there is a possibility that the mutual engagement betweenthe two connectors 1 and 2 can be removed by vibrations applied theretowhile the automobile is running and thus the electrical system of theautomobile can be dysfunctional to thereby incur an accident.

In view of this, conventionally, after the engagement step is completed,there has been carried out a conduction test which checks the connectorsto confirm that they are fully engaged.

However, as shown in FIG. 29, even in the partially engaged condition,when the mutual engagement length between the two connectors 1 and 2 isrelatively large, there can occur a case in which the female- andmale-type terminals respectively stored within their associatedconnectors 1 and 2 can be connected together electrically. Inparticular, contact resistance caused by the connection of the male- andfemale-type terminals can maintain the mutually connected conditionbetween the two connectors. As a result, there is a possibility that theconduction test will provide a positive conduction test result despitethe fact that the connectors are not fully engaged; that is, the partialengagement between the two connectors can be overlooked.

In view of the above, for example, in Japanese Patent Publication No.9-180820 of Heisei and the like, there is proposed a partial engagementpreventive connector lock mechanism in which, in order to be able todetect the partial engaged condition through the conduction test, thereare provided within the connector housings compression springs which areused to apply repulsive forces to the male and female connectors 1 and 2in their mutually removing directions.

With the use of this structure, if the repulsive forces (springconstants) of the compression springs are set larger than the contactresistance caused by the mutual connection between the male and femaleterminals, then, when the connectors are engaged together in a partialengaged condition, the two connectors 1 and 2 can be forced apart fromeach other by the repulsive forces of the compression springs until themutually connected condition between the male- and female-type terminalsis removed, which makes it possible to detect the partial engagementcondition positively.

However, with use of the above-mentioned structure which employs thecompression springs which are separate parts, not only the number ofparts required in the connectors and the number of assembling stepsthereof increase, which in turn increases the cost of the connector, butalso a storage space for the compression springs within the connectormust be provided, thereby increasing the sizes of the connectors.

SUMMARY OF THE INVENTION

The present invention aims at eliminating the above-mentioned drawbacksfound in the conventional connector lock mechanisms. Accordingly, it isan object of the invention to provide a connector lock mechanism whichdoes not incur an increase in the number of parts required in connectorsand the number of assembling steps thereof, but is positively able todetect the engaged condition between the male and female connectors.

In attaining the above object, according to the present invention, thereis provided a connector lock mechanism for locking the connectedcondition of a set of male and female connectors, the connector lockmechanism comprising: a flexible arm so disposed on one of the male andfemale connectors as to extend along a direction in which one connectorcan be engaged with the other connector; an engaging portion disposed onthe flexible arm; an arm guide surface disposed on the other connectorfor flexing the flexible arm until the length of the mutual engagementbetween the two connectors reaches a preset length; and, securing meansdisposed on the other connector and, when the connector mutualengagement length reaches the preset length, being capable of securingthe engaging portion of the flexible arm to thereby prevent the twoconnectors from being removed from each other.

In particular, the present connector lock mechanism is characterized bya connector removing mechanism which comprises: a flexible elastic pieceformed integrally with one connector; and, a push-out guide surfacewhich is formed integrally with the other connector and also which, whenthe male and female connectors are operated for their mutual engagement,deforms the flexible elastic piece elastically to thereby generate apush-out force separating the two connectors from each other in theirmutually removing directions, while the elasticity of the flexibleelastic piece and the inclination angle of the push-out guide surfaceare set such that the push-out force to be generated by the connectorremoving mechanism is greater than contact resistance caused by mutualconnection between male- and female-type terminals respectively heldwithin their associated connectors.

According to the above-structured connector lock mechanism, when a setof male and female connectors are operated for their mutual engagement,the connector removing mechanism generates a push-out force whichseparates or removes the set of male and female connectors from eachother in their mutually removing directions. Since the push-out force tobe generated by the connector removing mechanism is set larger than thecontact resistance caused by the mutual connection between the male- andfemale-type terminals respectively stored within their associatedconnectors, if the male and female connectors are partially engaged witheach other, then both of the two connectors are pushed back in theirmutually removing directions at least until the mutually connectedcondition between the male- and female-type terminals is removedcompletely, which makes it possible to detect the partially engagedcondition between the two connectors without fail.

Also, the flexible elastic piece and push-out guide surface forming theconnector removing mechanism are respectively formed integrally withtheir associated connectors. Therefore, when compared with aconventional mechanism which uses separate parts such as compressionsprings, not only the reliability of the connectors can be secured butalso the costs of the connectors can be reduced without incurring anyinconveniences, for example, without increasing the number of partsrequired in the connectors and the number of the assembling stepsthereof.

Also, in the above-mentioned connector lock mechanism, preferably, theflexible arm may also serve as the flexible elastic piece and the armguide surface may also serve as the push-out guide surface. That is, inthe present preferred embodiment, the respective connectors can besimplified in structure, which in turn can enhance the moldability ofthe connectors.

Further, in the above-mentioned connector lock mechanism, preferably,within the range of the above-mentioned mutual engagement between themale and female connectors, the inclination angle of the push-out guidesurface may be changed properly in the intermediate portion thereof insuch a manner that a greater push-out force can be generated in therange of the mutual connection between the above-mentioned male- andfemale-type terminals than in the unconnected condition between themale- and female-type terminals. That is, in the thus structuredpreferred embodiment, in the unconnected condition between the male- andfemale-type terminals in which the mutual resistance between the male-and female-type terminals does not act, the push-out force to begenerated by the connector removing mechanism can be controlled to aminimum, which makes it possible to save an operation force necessaryfor mutual engagement between the male and female connectors. Therefore,the operation for mutual engagement between the male and femaleconnectors can be improved in efficiency.

Still further, in the above-mentioned connector lock mechanism,preferably, the flexible elastic piece may be formed integrally with theflexible arm, and a wrong operation preventive piece, which is used toprevent the male and female connectors from being engaged with eachother while the flexible arm is flexed in its locking removed condition,may be formed integrally with the flexible arm. That is, in the presentpreferred embodiment, even if the mutual engagement between the male andfemale connectors is executed in error while the flexible arm is flexedin its locking removed condition, the connector removing mechanism isprevented from operating normally in a condition where the position ofthe flexible elastic piece is shifted from the position of the push-outguide surface. Therefore, the mutual engagement between the male andfemale connectors due to the inadvertent flexing of the flexible arm canbe prevented, thereby being able to enhance the reliability of theconnector removing mechanism.

Yet further, in the above-mentioned connector lock mechanism,preferably, the above-mentioned flexible elastic piece and push-outguide surface may be provided in two or more sets. That is, in thepresent preferred embodiment, if the operation timings of the respectivesets of flexible elastic pieces and push-out guide surfaces are shiftedfrom one another, then the push-out force to be generated by theconnector removing mechanism can be made to vary. Also, if the two ormore sets of flexible elastic pieces and push-out guide surfaces areoperated simultaneously, then a large push-out force can be providedeasily. Therefore, even if the number of terminals to be stored withinthe respective connectors is large, there can be obtained a necessaryand sufficient push-out force.

Moreover, in the above-mentioned connector lock mechanism, preferably,while the flexible arm is held in its flexed condition, a push-out forceacting on the male and female connectors in their mutually removingdirections may be always generated due to the flexed condition of theflexible elastic piece; and, if the male and female connectors areengaged with each other completely, then the flexed conditions of theflexible arm and flexible elastic piece may be removed, thereby beingable to remove the push-out force acting on the male and femaleconnectors in their mutually removing directions. Therefore, when themale and female connectors are completely engaged with each other, theflexible elastic piece, together with the flexible arm, can be returnedto its original condition, which makes it possible to prevent thefatigue of the flexible elastic piece caused by the long flexedcondition thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a first embodiment of aconnector lock mechanism according to the invention;

FIG. 2 is a perspective view of the main portions of a female connectorshown in FIG. 1;

FIG. 3 is an explanatory view of the operation of the first embodimentshown in FIG. 1, wherein FIG. 3(a) shows an initial condition of mutualengagement between male and female connectors in the first embodiment,FIG. 3(b) shows an intermediate condition of the connector mutualengagement, and FIG. 3(c) shows a completed condition of the connectormutual engagement;

FIG. 4 is an explanatory view of the operation of the mutually connectedcondition between male- and female-type terminals respectively storedwithin their associated connectors shown in FIG. 1, in particular, FIG.4(a) shows an unconnected condition between the male- and female-typeterminals, and FIG. 4(b) shows a completely connected condition betweenthe male- and female-type terminals;

FIG. 5 is an explanatory view of the relation between a push-out forceand an engagement length in the first embodiment shown in FIG. 1;

FIG. 6 is a plan view of the main portions of a second embodiment of aconnector lock mechanism according to the invention;

FIG. 7 is an explanatory view of the relation between a push-out forceand an engagement length in the second embodiment shown in FIG. 6;

FIG. 8 is an exploded perspective view of a third embodiment of aconnector lock mechanism according to the invention;

FIG. 9 is a longitudinal section view of an initial condition of theconnector mutual engagement in the third embodiment shown in FIG. 8;

FIG. 10 is a plan view of the main portions of the third embodimentshown in FIG. 8, showing an operation for mutual engagement between maleand female connectors, in particular, FIG. 10(a) shows an initialcondition of the connector mutual engagement, and FIG. 10(b) shows acomplete condition of the connector mutual engagement;

FIG. 11 is an exploded perspective view of a fourth embodiment of aconnector lock mechanism according to the invention;

FIG. 12 is a plan view of the main portions of the fourth embodimentshown in FIG. 11, showing an operation for mutual engagement betweenmale and female connectors in the fourth embodiment, in particular, FIG.12(a) shows an initial condition of the connector mutual engagement, andFIG. 12(b) shows a complete condition of the connector mutualengagement;

FIG. 13 is an exploded perspective view of a fifth embodiment of aconnector lock mechanism according to the invention;

FIG. 14(a) and FIG. 14(b) are longitudinal section views of the fifthembodiment shown in FIG. 13, showing a partially engaged conditionbetween male and female connectors in the fifth embodiment;

FIG. 15 is a plan view of the main portions of the fifth embodimentshown in FIG. 13, in particular, FIG. 15(a) shows an initial conditionof mutual engagement between male and female connectors in the fifthembodiment, and FIG. 15(b) shows a complete condition of the mutualengagement between the male and female connectors;

FIG. 16 is an exploded perspective view of a sixth embodiment of aconnector lock mechanism according to the invention;

FIG. 17 is a longitudinal section view of the sixth embodiment shown inFIG. 16, showing a state thereof before the male and female connectorsthereof are engaged together;

FIG. 18 is a longitudinal section view of the sixth embodiment shown inFIG. 16, showing a partially engaged condition of the mutual engagementbetween the male and female connectors;

FIG. 19 is a longitudinal section view of the sixth embodiment shown inFIG. 16, showing a completely engaged condition of the mutual engagementbetween the male and female connectors;

FIG. 20 is an exploded perspective view of a seventh embodiment of aconnector lock mechanism according to the invention;

FIG. 21 is a longitudinal section view of the seventh embodiment shownin FIG. 20, showing a partially engaged condition of the mutualengagement between male and female connectors in the seventh embodiment;

FIG. 22 is a longitudinal section view of the seventh embodiment shownin FIG. 20, showing a completely engaged condition of the mutualengagement between the male and female connectors;

FIG. 23 is an explanatory view of the seventh embodiment shown in FIG.20, showing the relation between a push-out force and an engagementlength in the seventh embodiment;

FIG. 24 is an exploded perspective view of an eighth embodiment of aconnector lock mechanism according to the invention;

FIG. 25 is a longitudinal section view of the eighth embodiment shown inFIG. 24, showing an intermediate condition of mutual engagement betweenmale and female connectors in the eighth embodiment;

FIG. 26 is a longitudinal section view of the eighth embodiment shown inFIG. 24, showing a completely engaged condition of the mutual engagementbetween the male and female connectors;

FIG. 27 is an explanatory view of the eighth embodiment shown in FIG.24, showing the relation between a push-out force and an engagementlength in the eighth embodiment;

FIG. 28 is a perspective view of male and female connectors, showing aconventional connector lock mechanism; and,

FIG. 29 is a perspective view of the conventional connector lockmechanism shown in FIG. 28, showing a partially engaged condition ofmutual engagement between male and female connectors in the conventionalconnector lock mechanism.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, description will be given hereinbelow in detail of the preferredembodiments of a connector lock mechanism according to the inventionwith reference to the accompanying drawings.

At first, description will be given below of a first embodiment of aconnector lock mechanism according to the invention with reference toFIGS. 1 to 5. In particular, FIG. 1 is an exploded perspective view ofthe first embodiment of a connector lock mechanism according to theinvention; FIG. 2 is a perspective view of the main portions of a femaleconnector shown in FIG. 1; FIG. 3 is an explanatory view of theoperation of the first embodiment shown in FIG. 1; FIG. 4 is anexplanatory view of the operation of the mutually connected conditionbetween male and female terminals which produce the contact resistancewhen they are engaged together; and FIG. 5 is an explanatory view ofvariations in push-out forces which are caused to occur in a connectorremoving mechanism employed in the first embodiment shown in FIG. 1.

A connector lock mechanism 31 according to the first embodiment of theinvention comprises a set of male and female connectors 32 and 33. Oneof the two connectors, that is, the male connector 32, includes a pairof flexible arms 35 and 36 which respectively extend in a directionwhere the male connector 32 can be engaged with the other connector 33or female connector 33 (in FIG. 1, in a direction of an arrow A) andalso which include engaging portions 38 respectively formed in theirrespective leading end portions thereof. The male connector 32 alsoincludes two terminal storage chambers 32 a therein in which twofemale-type terminals are respectively stored and retained.

The two flexible arms 35 and 36 respectively rise up from the rear endside of the housing upper wall of the male connector 32 and then extendtoward the front end side thereof, while the rising base portions of theflexible arms 35 and 36 are joined together and are thus integrated intoa united body. Also, the two flexible arms 35 and 36 are formed in sucha manner that they are spaced from each other in the width (or lateral)direction of the male connector 32 and extend parallel to each other.Further, the engaging portions 38 of the flexible arms 35 and 36respectively consist of projections which are formed in such a manner asto project outwardly in lateral direction of the male connector 32 fromthe respective leading end portions of their associated flexible arms 35and 36. Each of the engaging portions 38 includes a tapered surfacewhich is gradually inclined outwardly from the front end side of theconnector housing toward the rear end side thereof.

On the other hand, the other connector, that is, the female connector33, comprises a pair of arm guide surfaces 40 and 41 which respectivelyinclude securing means 43. The pair of arm guide surfaces 40 are capableof flexing the flexible arms 35 and 36 inwardly until the length of themutual engagement between the male and female connectors reaches apreset length, while the securing means 43 are respectively formedintegrally with their associated guide surfaces 40 and 41. When themutual engagement length reaches the preset length, the securing meansare capable of securing their associated engaging portions 38 of themale connector 32 to thereby lock the mutually engaged condition of themale and female connectors. The female connector 33 stores and holdstherein two male-type terminals which respectively correspond to thepartner male connector 32.

Also, as shown in FIGS. 2 and 3, the two arm guide surfaces 40 and 41 ofthe female connector 33 are respectively formed in the upper portions ofthe two inner side surfaces of the connector housing in such a mannerthat their associated engaging portions 38 and 38 of the male connector32 can contact them when the two connectors are engaged with each other.The arm guide surfaces 40 and 41 respectively include tapered surfaceswhich are able to flex their associated flexible arms 35 and 36 inwardlyas the connector mutual engagement advances. Also, the securing means 43consist of stepped portions which are respectively formed in the rearend portions of the two arm guide surfaces 40 and 41 in such a manner asto be able to secure their associated engaging portions 38 of the maleconnector 32.

Next, description will be given below of an engaging operation to beexecuted for the mutual engagement of the above-mentioned male andfemale connectors 32 and 33.

At first, in the initial stage of the connector engagement, as shown inFIGS. 3a and 4 a, a male-type terminal 45 stored within the femaleconnector 33 is not in contact with a female-type terminal 46 storedwithin the male connector 32, that is, the two terminals 45 and 46 arenot connected together but are held in an unconnected condition.

If the mutual engagement between the male and female connectors advancesto a certain degree, then, as shown in FIGS. 3b and 4 b, the male- andfemale-type terminals 45 and 46, which are respectively stored withintheir associated connectors, begin to make contact with each other. Ifthe connector mutual engagement advances further, then, as shown in FIG.3c, when the engaging portions 38 of the male connectors 32 arerespectively engaged with the securing means 43 of the female connectors33, the male- and female-type terminals 45 and 46 of the two connectors33 and 32 are connected together, that is, they are held in a connectedcondition in which they are contacted together with a sufficientengagement length for electrical connection.

Also, when the engaging portions 38 of the two flexible arms 35 and 36of the male connector 32 are respectively engaged with the securingmeans 43 of the female connector 33, the flexed conditions of the twoflexible arms 35 and 36 return to their respective original conditions.Thus, since the engaging surfaces of the flexible arms 35 and 36 extendat right angles to the connector engaging direction, the engagingsurfaces of the flexible arms 35 and 36 prevent the male and femaleconnectors from moving in their mutually removing directions, so thatthe mutually engaged condition of the male and female connectors can belocked.

In the connector lock mechanism 31 according to the present embodiment,the two flexible arms 35, 36 and two arm guide surfaces 40, 41 functionas a connector removing mechanism 48. In other words, the presentconnector removing mechanism 48 is composed of the two flexible arms 35,36 which are formed integrally with the male connector 32 and functionas flexible elastic pieces, and the two arm guide surfaces 40, 41 whichare formed integrally with the female connector 33 and function aspush-out guide surfaces. Additionally, when the two, male and female,connectors are engaged together, the two arm guide surfaces 40, 41serving as the push-out guide surfaces deform elastically the twoflexible arms 35, 36 serving as the flexible elastic pieces to therebygenerate a push-out force F which pushes out the male and femaleconnectors in their mutually removing directions against the movementsof the two connectors in their mutually engaging directions (see FIG.3b).

Referring now to the above in more detail, the inclination angles of theflexible arms 35, 36 and arm guide surfaces 40, 41 are set in such amanner that the push-out force F to be generated by the connectorremoving mechanism 48 is larger than mutual contact resistance caused byand between the male- and female-type terminals 45 and 46 stored withintheir respective connectors.

As shown in FIG. 5, the characteristic line F1 of the connector removingmechanism 48 shows the relation between the push-out force F andconnector mutual engagement length L, whereas a characteristic curvedline G1 shows the relation between the mutual contact resistance of themale and female terminals 45, 46 and connector mutual engagement lengthwhen the two male and female connectors are engaged together.

The push-out force F that is generated by the connector removingmechanism 48 is a reaction force which is given from the arm guidesurfaces 40, 41 and increases up to a level just before the connectormutual engagement length L reaches a locked condition, that is, acondition shown by a preset length LE (see FIG. 3c).

Also, the mutual contact resistance G between the male- and female-typeterminals 45 and 46, as shown in FIG. 4b, increases greatly at and froman engagement length L_(M) where a contact spring 46 a disposed withinthe female-type terminal 46 begins to make contact with the male-typeterminal 45.

As described above, in the connector lock mechanism 31 according to thepresent embodiment, when a set of male and female connectors 32 and 33are engaged with each other, the connector removing mechanism 48generates the push-out force F which pushes the male and femaleconnectors 32 and 33 away from each other. Because the push-out force Fto be generated by the connector removing mechanism 48 is set largerthan the mutual contact resistance caused by and between the male andfemale terminals 45 and 46 respectively stored within their associatedconnectors, when the two connectors are held in their mutually partiallyengaged condition, both of the male and female connectors are caused tomove in their mutually removing directions at least until the mutuallyconnected condition between the male and female terminals 45 and 46 isremoved.

Therefore, the present connector lock mechanism 31 is surely able todetect the mutually partially engaged condition between the male andfemale connectors and thus is surely able to prevent the possibleoverlooking of such connector partially engaged condition.

Also, since the flexible arms 35, 36 and arm guide surfaces 40, 41forming the connector removing mechanism 48 are all formed integrallywith their associated connector housings, when compared with theconventional connector lock mechanism which uses separate parts such ascompression springs or the like, according to the present connector lockmechanism, the number of parts required in the connectors as well as thenumber of assembling steps thereof can be reduced, which makes itpossible not only to secure the reliability of the connectors but alsoto reduce the manufacturing costs thereof.

Further, according to the present embodiment, the flexible arms 35 and36 also serve as the flexible elastic pieces of the connector removingmechanism 48, while the arm guide surfaces 40 and 41 also serve as thepush-out guide surfaces of the connector removing mechanism 48.Therefore, the structures of the respective connectors can besimplified, which makes it possible to enhance the moldability thereofas well as the yield rate of the products.

Next, description will be given below in detail of a second embodimentof a connector lock mechanism according to the invention with referenceto FIGS. 6 and 7. In particular, FIG. 6 is an explanatory view of theoperation of a connector lock mechanism according to the secondembodiment of the invention, while FIG. 7 is an explanatory view ofvariations in the push-out force of a connector removing mechanismaccording to the second embodiment.

As shown in FIG. 6, in a connector lock mechanism 51 according to thesecond embodiment, the arm guide surfaces 40 and 41 employed in theconnector lock mechanism 31 according to the first embodiment of theinvention are improved, and the remaining portions of the connector lockmechanism 51 are similar in structure those of the first embodiment.

That is, according to the present embodiment, the flexible arms 35, 36and engaging portions 38 respectively provided in the male connector 32are the same as in the first embodiment, while the flexible arms 35 and36 function as the flexible elastic pieces of the connector removingmechanism 48. In a female connector 53 which is an engaging partnerconnector of the male connector, there are formed arm guide surfaces 54and 55 which are capable of flexing the flexible arms 35 and 36 when themale and female connectors 32 and 53 are operated for their mutualengagement. The arm guide surfaces 54 and 55 can serve as the push-outguide surfaces of the connector removing mechanism 48.

Referring in detail to the structure of the arm guide surfaces 54 and 55according to the present embodiment, the inclination angles of the armguide surfaces 54 and 55 functioning as the push-out guide surfaces arechanged in their respective intermediate portions in order that, withinthe mutually engaged range of the male and female connectors 32 and 53,a larger push-out force can be generated in the mutually connected rangeof the male- and female-type terminals respectively stored within thetheir associated connectors than in an unconnected range in which themale and female terminals are not contacted with each other.

In other words, the arm guide surfaces 54 and 55 serving as the push-outguide surfaces are each composed of a first tapered surface T1 which isdisposed in the front portion of the associated guide surface and issmoothly inclined, and a second tapered surface T2 which is disposed inthe rear portion of the associated guide surface and is steeplyinclined. Since the arm guide surfaces 54 and 55 are each composed ofsuch two tapered surfaces having different inclination angles, thepush-out force F to be generated by the connector removing mechanism 48provides a characteristic line F2 as shown in FIG. 7.

As described above, in the connector lock mechanism 51 according to thepresent embodiment, the inclination angles of the arm guide surfaces 54and 55 functioning as the push-out guide surfaces of the connectorremoving mechanism 48 are changed in their respective intermediateportions. For this reason, in the unconnected range in which the mutualcontact resistance between the male and female terminals is not present,the push-out force F to be generated by the connector removing mechanism48 can be controlled to a minimum. This not only can minimize anoperation force necessary for mutual engagement between the male andfemale connectors but also makes it possible to carry out an operationfor mutual engagement between the connectors with higher efficiency.

Next, description will be given below in detail of a third embodiment ofa connector lock mechanism according to the invention with reference toFIGS. 8 to 10. In particular, FIG. 8 is an exploded perspective view ofthe third embodiment of a connector lock mechanism according to theinvention, FIG. 9 is a longitudinal section view of an initial conditionof the connector engagement in the third embodiment shown in FIG. 8, andFIG. 10 is an explanatory view of an operation for mutual engagementbetween the male and female connectors in the third embodiment shown inFIG. 8.

Specifically, a connector lock mechanism 57 according to the presentembodiment relates to a set of male and female connectors 59 and 60. Oneof the two connectors, namely, the male connector 59, includes a singleflexible arm 62 formed in such a manner as to extend along a directionthereof in which the male connector 59 can be engaged with the otherconnector, namely, the female connector 60, while the flexible arm 62includes an engaging portion 63 formed integrally therewith. The maleconnector 59 further includes two terminal storage chambers 59 a whichare formed in the width direction of the male connector 59 and arecapable of storing therein their respective female-type terminals.

The flexible arm 62 is structured such that it rises up from the rearend side of the housing of the male connector 59 and then extends towardthe front end side thereof. Also, the engaging portion 63 is aprojection which is provided in the leading end portion of the flexiblearm 62 in such a manner as to project upwardly, while the upwardlyprojecting length of the engaging portion 63 increases gradually fromthe front end side of the connector housing toward the rear end sidethereof.

On the other hand, the other connector, namely, the female connector 60includes an arm guide surface 65 capable of downwardly flexing theflexible arm 62 until the mutual engagement length between the twoconnectors reaches a preset length, and securing means 66 which, whenthe connector mutual engagement length reaches the preset length, cansecure the engaging portion 63 to thereby lock the connector mutuallyengaged condition. The arm guide surfaces 65 and securing means 66 areboth formed integrally with the female connector 60. The femaleconnector 60 also has two male-type terminals which respectivelycorrespond to the female-type terminals stored within the male connector59.

As shown in FIG. 9, the arm guide surface 65 is disposed in the innersurface of the upper wall of the female connector 60 in such a mannerthat, when the male and female connectors 59 and 60 are operated formutual engagement, the engaging portion 63 can be contacted with the armguide surface 65. In operation, the arm guide surface 65 flexes theflexible arm 62 downwardly as the connector mutual engagement advances.Also, the securing means 66 consists of a rectangular-shaped securinghole which is formed in the rear end portion of the arm guide surface 65in such a manner that the engaging portion 63 can be fitted into thesecuring hole 66.

If the engaging portion 63 of the flexible arm 62 is engaged with thesecuring means 66 of the female connector 60, the flexed flexible arm 62returns to its original condition. When the engaging portion 63 isengaged with the securing means 66, the respective engaging surfacesthereof prevent the male and female connectors from moving in theirmutually removing directions because the engaging surfaces extend atright angles to the mutually engaging directions of the male and femaleconnectors, so that the mutually engaged condition of the male andfemale connectors can be locked.

The present connector lock mechanism 57 further includes a connectorremoving mechanism 70. The present connector removing mechanism 70 iscomposed of two flexible elastic pieces 68 respectively formedintegrally with the male connector 59, and two push-out guide surfaces69 which are formed integrally with the female connector 60 and alsowhich are capable of elastically deforming their associated flexibleelastic pieces 68 in the connector mutual engagement to thereby generatea push-out force pushing back the male connector 59 in the engagementremoving direction.

The two flexible elastic pieces 68 are respectively formed in such amanner that they project from the two side surfaces of the flexible arm62 located near to the leading end portion thereof. As shown in FIG. 9,the two push-out guide surfaces 69 are respectively provided on the twoside surfaces of the upper portion of the housing of the femaleconnector 60 at the height position where their associated flexibleelastic pieces 68 can be contacted with the push-out guide surfaces 69when the flexible arm 62 is flexed downwardly by the arm guide surface65.

Also, as shown in FIG. 10a, the two push-out guide surfaces 69 arerespectively tapered surfaces which are capable of flexing a pair offlexible elastic pieces 68 and 68 as the mutual engagement between themale and female connectors advances.

Further, according to the present connector removing mechanism 70, theelasticity of the flexible elastic pieces 68 and the inclination anglesof the push-out guide surfaces 69 are set in such a manner that thepush-out force to be generated by the flexing of the flexible elasticpieces 68 should be larger than the mutual contact resistance betweenthe male- and female-type terminals respectively stored within theirassociated connectors.

As shown in FIG. 10b, when the connector mutual engagement lengthreaches a preset length and thus the engaging portion 63 is engaged withthe securing means 66, the flexible elastic pieces 68 pass beyond therear ends of their associated push-out guide surfaces 69 so that theyare free from the pressures of their associated push-out guide surfaces69. By the way, the push-out force F to be generated by the connectorremoving mechanism 70 has the same characteristic line as thecharacteristic line F1 shown in FIG. 5.

As described above, in the connector lock mechanism 57 according to thepresent embodiment, when a set of male and female connectors 59 and 60are engaged together, the connector removing mechanism 70 generates thepush-out force which pushes the set of male and female connectors 59 and60 in directions where they are removed from each other. Since thepush-out force to be generated by the connector removing mechanism 70 isset larger than the mutual contact resistance between the male- andfemale-type terminals respectively stored within their associatedconnectors, in a partially engaged condition where the male and femaleconnectors are partially engaged with each other, the two connectors areboth pushed away from each other at least until the mutually connectedcondition between the male- and female-type terminals is removed. Thismakes it possible to detect the partially engaged condition between themale and female connectors positively, thereby being able to surelyprevent the possible overlooking of the partially engaged condition.

Also, because the flexible elastic pieces 68 and push-out guide surfaces69 forming the connector removing mechanism 70 are respectively formedintegrally with their associated connector housings, when compared withthe conventional connector removing mechanism using separate parts suchas compression springs, the number of parts required in the connectorsas well as the number of assembling steps thereof can be reduced, whichmakes it possible to reduce the manufacturing costs of the connectors.

Next, description will be given below in detail of a fourth embodimentof a connector lock mechanism according to the invention with referenceto FIGS. 11 and 12. In particular, FIG. 11 is an exploded perspectiveview of the fourth embodiment of a connector lock mechanism according tothe invention, and FIG. 12 is an explanatory view of an operation formutual engagement between the male and female connectors in the fourthembodiment shown in FIG. 11.

Specifically, a connector lock mechanism 72 according to the presentembodiment comprises a set of male and female connectors 73 and 74. Oneof the two connectors, namely, the male connector 73 includes a singleflexible arm 76 formed in such a manner as to extend along a directionthereof in which the male connector 73 can be engaged with the otherconnector, namely, the female connector 74, while the flexible arm 76includes an engaging portion 77 formed integrally therewith. Theflexible arm 76 is provided on the housing of the male connector 73 insuch a manner that it rises up from the rear end side of the maleconnector 73 housing and then extends toward the front end side thereof.

The engaging portion 77 consists of a projection which is formed on theflexible arm 76 in such a manner as to project upwardly therefrom, whilethe upwardly projecting length of the engaging portion 77 increasesgradually from the front end side of the connector housing toward therear end side thereof. The present male connector 73 includes, in thewidth direction thereof, two terminal storage chambers 73 a which arecapable of storing their associated female-type terminals therein.

On the other hand, the other connector, namely, the female connector 74includes an arm guide surface 78 capable of flexing the flexible arm 76until the mutual engagement length between the male and femaleconnectors reaches a preset length. The arm guide surface 78 includessecuring means 79 which is formed integrally with the arm guide surface78 and also which, when the connector mutual engagement length reachesthe preset length, can secure the engaging portion 77 to thereby lockthe connector mutually engaged condition. The arm guide surface 78 isformed in the inner upper surface of the housing of the female connector74 in such a manner that the engaging portion 77 can be contacted withthe arm guide surface 78 when the male and female connectors 73 and 74are operated for their mutual engagement. Thus, in operation, the armguide surface 78 is able to flex the flexible arm 76 as the mutualengagement between the male and female connectors advances. Also, theengaging means 79 consists of a rectangular-shaped securing hole whichis formed in the rear end portion of the arm guide surface 78 in such amanner that the engaging portion 77 can be engaged with the engagingmeans 79. Naturally, the female connector 74 includes two male-typeterminals which correspond the female-terminals stored within the maleconnector 73.

In the mutual engagement between the above-structured male and femaleconnectors 73 and 74, when the engaging portion 77 of the flexible arm76 of the male connector 73 is engaged with the securing means 79 of thefemale connector 74, the flexible arm 76 is returned from the flexedcondition to its original condition. And, if the engaging portion 77 isengaged with the securing means 79, then their respective engagingsurfaces prevent the male and female connectors from moving in theirmutually removing directions because they intersect at right angles tothe connector mutual engaging direction, so that the mutually engagedcondition between the male and female connectors can be locked.

In the connector lock mechanism 72 according to the present embodiment,there is provided a connector removing mechanism 83. In particular, thepresent connector removing mechanism 83 is composed of two flexibleelastic pieces 80 respectively formed integrally with the male connector73, and two push-out guide surfaces 81 respectively formed integrallywith the female connector 74 and also, when the male and femaleconnectors are operated for their mutual engagement, capable ofelastically deforming their associated flexible elastic pieces 80 tothereby generate a push-out force which pushes the male and femaleconnectors in their mutually removing directions where the connectormutual engagement can be removed.

The above-mentioned flexible elastic pieces 80 are respectively providedon the two sides of the flexible arm 76 of the housing of the maleconnector 73 in such a manner as to project directly therefrom, whilethe push-out guide surfaces 81 are respectively formed on the two sidesurfaces of the housing of the female connector 74 at such heightposition as their associated flexible elastic pieces 80 can be contactedwith the push-out surfaces 81.

As shown in FIG. 12, the push-out guide surfaces 81 are tapered surfaceswhich are capable of flexing their associated flexible elastic pieces 80inwardly as the connector mutual engagement advances.

In the above-mentioned connector removing mechanism 83, the elasticityof the flexible elastic pieces 80 and the inclination angles of thepush-out guide surfaces 81 are set in such a manner that the push-outforce to be generated by the flexing of the flexible elastic pieces islarger than the mutual contact resistance caused by and between the maleand female terminals.

When the mutual engagement length between the connectors reaches apreset length and thus the engaging portion 77 is engaged with thesecuring means 79, as shown in FIG. 12(b), the flexible elastic pieces80 respectively pass through their associated push-out guide surfaces 81while in contact therewith and are then secured to the rear ends oftheir associated push-out guide surfaces 81. It should be noted that thepush-out force of the present connector removing mechanism 83 providesthe same characteristic line as the characteristic line F1 shown in FIG.5.

In the above-mentioned connector lock mechanism 72 according to thepresent embodiment, when a set of male and female connectors 73 and 74are operated for their mutual engagement, the connector removingmechanism 83 generates the push-out force which pushes the male andfemale connectors in their mutually removing directions where the maleand female connectors 73 and 74 are removed from each other. Since thepush-out force to be generated by the connector removing mechanism 83 isset larger than the mutual contact resistance caused by and between themale- and female-type terminals respectively stored within theirassociated connectors, when the male and female connectors are partiallyengaged with each other, the male connector is pushed back in theremoving direction at least until the mutually connected conditionbetween the male- and female-type terminals is removed completely. Thismakes it possible to surely detect the half engagement between the maleand female connectors 73 and 74 without overlooking it.

Also, since the flexible elastic pieces 80 and push-out guide surfaces81 forming the present connector removing mechanism 83 are respectivelyformed integrally with their associated connectors, when compared withthe conventional connector removing mechanism which employs separateparts such as compression springs, the number of parts required in theconnectors as well as the number of assembling steps thereof can bereduced, thereby being able to reduce the manufacturing costs thereof.

Next, description will be given below in detail of a fifth embodiment ofa connector lock mechanism according to the invention with reference toFIGS. 13 to 15. In particular, FIG. 13 is an exploded perspective viewof the fifth embodiment of a connector lock mechanism according to theinvention, FIG. 14 is a longitudinal section view of the fifthembodiment shown in FIG. 13, showing a partially engaged conditionbetween the male and female connectors, and FIG. 15 is an explanatoryview of the operation of the mutual engagement between the male andfemale connectors in the fifth embodiment shown in FIG. 13.

Specifically, a connector lock mechanism 85 according to the presentembodiment relates to a set of male and female connectors 86 and 87. Oneof the two connectors, namely, the male connector 86 includes a singleflexible arm 88 formed in such a manner as to extend along a directionthereof (in FIG. 13, in the direction of an arrow D) in which the maleconnector 86 can be engaged with the other connector, namely, the femaleconnector 87, while the flexible arm 88 includes an engaging portion 89formed integrally therewith. The flexible arm 88 rises up from the frontend side of the male connector 86 housing and then extends toward therear end side and, the engaging portion 89 of the flexible arm 88projects upwardly from the upper surface of the flexible arm 88, whilethe projecting length of the engaging portion 89 increases graduallyfrom the front end side of the male connector 86 housing toward the rearend side thereof. It is noted that the present male connector 86includes in the width direction thereof two terminal storage chambers 86a respectively capable of storing female-type terminals therein.

On the other hand, the other connector, namely, the female connector 87includes an arm guide surface 91 with securing means 92 formedintegrally therewith. The arm guide surface 91 is capable of flexing theflexible arm 88 until the mutual engagement length between the male andfemale connectors reaches a preset length. The securing means 92 of thearm guide surface 91, when the mutual engagement length reaches thepresent length, is capable of securing the engaging portion 89 of theflexible arm 88 to thereby lock the mutually engaged condition betweenthe male and female connectors. Also, the securing means 92 consists ofa rectangular-shaped securing hole which is formed in front of the armguide surface 91 in such a manner that the engaging portion 89 of theflexible arm 88 can be fitted into the securing means 92. The presentfemale connector 87 stores and holds therein two male-type terminalswhich corresponds to the female-type terminals held within the maleconnector 86.

As shown in FIG. 14, the arm guide surface 91 is formed on the sidesurface of the housing of the female connector 87 in such a manner that,when the male and female connectors 86 and 87 are operated for theirmutual engagement, the engaging portion 89 of the flexible arm 88contact the arm guide surface 91. The flexible arm 88 is graduallyflexed downwardly as the connector mutual engagement advances. However,when the engaging portion 89 of the flexible arm 88 is engaged with thesecuring means 92 of the female connector 87, the flexible arm 88 isreturned from the flexed condition back to its original condition. Inthis operation, because the engaging surfaces thereof intersect at rightangles to the connector engaging direction, they prevent the male andfemale connectors from moving in their mutually removing directions tothereby lock the mutually engaged condition between the male and femaleconnectors.

In the connector lock mechanism 85 according to the present embodiment,one connector, namely, the male connector 86, includes a pair offlexible elastic pieces 94 respectively formed integrally with the maleconnector 86. The pair of flexible elastic pieces 94 are respectivelyarranged in such a manner that they project laterally from the theirassociated side surfaces of the flexible arm 88 of the male connector86.

Also, the other connector, namely, the female connector 87, includes apair of push-out guide surfaces 95 respectively formed integrally withthe female connector 87. The push-out guide surfaces 95, when the maleand female connectors 86 and 87 are engaged with each other, are capableof deforming the flexible elastic pieces 94 to thereby generate apush-out force which pushes back the male and female connectors in theirmutually removing directions. The push-out guide surfaces 95 andflexible elastic pieces 94 cooperate together in forming a connectorremoving mechanism 96.

As shown in FIGS. 13 and 15, the push-out guide surfaces 95 arerespectively formed on the two side surfaces of the female connector 87at such a height that, while the flexible arm 88 is flexed, the flexibleelastic pieces 94 on the flexible arm 88 can be respectively contactedwith the push-out guide surfaces 95. Further, as shown in FIGS. 14(a)and 15(a), the push-out guide surfaces 95 respectively consist oftapered surfaces which are able to flex their associated flexibleelastic pieces 94 inwardly as the connector engagement advances.

In a state where the flexible elastic pieces 94 are held in contact withtheir associated push-out guide surfaces 95 during the flexed conditionof the flexible arm 88, there is always generated the push-out forcewhich pushes back the male and female connectors in their mutuallyremoving directions.

Here, in the connector removing mechanism 96 according to the presentembodiment, the elasticity of the flexible elastic pieces 94 and theinclination angles of the push-out guide surfaces 95 are set in such amanner that the push-out force to be generated by the flexing of theflexible elastic pieces 94 is larger than the mutual contact resistancecaused by and between male-type and female-type terminals which arerespectively stored within the two connectors.

When the male and female connectors are engaged together completely,that is, when the mutual engagement length between the male and femaleconnectors reaches a preset length, the engaging portion 89 of theflexible arm 88 is engaged with the securing means 92 of the arm guidesurface 91 and the flexed condition of the flexible arm 88 is removed.In addition, as shown in FIGS. 14(b) and 15(b), the flexible elasticpieces 94 pass beyond the end of the push-out guide surface 95 and isthereby removed from the push-out guide surface 95 (in FIG. 14(b), theformer is removed upwardly from the latter) and, at the same time, thepush-out force acting in the connectors mutually removing directions isalso removed. Therefore, in the connector complete engagement, theflexible elastic pieces 94 are returned back to their originalconditions together with the flexible arm 88, which makes it possible toprevent the possible fatigue of the flexible pieces 94 caused by holdingthe flexible pieces 94 in the flexed condition for a long period oftime. By the way, the push-out force to be generated by the connectorremoving mechanism 96 provides the same characteristic line as thecharacteristic line F1 shown in FIG. 5.

As described above, in the connector lock mechanism 85, when the set ofmale and female connectors 86 and 87 are operated for their mutualengagement, the connector removing mechanism 96 always applies to themale and female connectors 86 and 87 the push-out force which pushesthem in their mutually removing directions. Since the push-out force tobe generated by the connector removing mechanism 96 is set larger thanthe mutual contact resistance between the male-type and female-typeterminals which are respectively stored within the two connectors, whenthe two connectors are partially engaged with each other, the twoconnectors are pushed back in their mutually removing directions atleast until the mutually connected condition between the male- andfemale-type terminals is removed. Therefore, the present connector lockmechanism 85 is surely able to detect the partially engaged conditionbetween the male and female connectors without fail.

Also, the flexible elastic pieces 94 and push-out guide surfaces 95forming the present connector removing mechanism 96 are respectivelyprovided in their associated connectors in such a manner that they areformed integrally therewith. That is, when compared with theconventional connector removing mechanism which uses separate parts suchas compression springs or the like, the present connectorremoving-mechanism 96 can reduce the number of parts required in theconnectors as well as the number of assembling steps thereof, which inturn makes it possible to reduce the manufacturing costs thereof.

Next, description will be given below in detail of a sixth embodiment ofa connector lock mechanism according to the invention with reference toFIGS. 16 to 19. In particular, FIG. 16 is an exploded perspective viewof the sixth embodiment of a connector lock mechanism according to theinvention, FIG. 17 is a longitudinal section view of male and femaleconnectors respectively shown in FIG. 16, FIG. 18 is a longitudinalsection view of the sixth embodiment, showing a mutually partiallyengaged condition between the male and female connectors shown in FIG.16, and FIG. 19 is a plan view of the main portions of the sixthembodiment shown in FIG. 16, showing a completely engaged conditionbetween the male and female connectors thereof.

Specifically, a connector lock mechanism 98 according to the presentembodiment relates to a set of male and female connectors 99 and 100. Inparticular, one of the two connectors, namely, the male connector 99includes a pair of flexible arms 102 and 102 which are respectivelyformed in such a manner as to extend along a direction thereof (in FIG.16, in a direction of an arrow E) in which the male connector 99 can beengaged with the other connector, namely, the female connector 100,while each of the flexible arms 102 includes an engaging portion 103which is formed integrally therewith. Each of the present flexible arms102 is provided on the housing of the male connector 99 in such a mannerthat it rises up from the front end side of the male connector 99housing and then extends toward the rear end side thereof. The free endportions of the two flexible arms 102, which are situated in the rearend side of the male connector housing 99, are connected together tothereby form an operation portion which can be used to remove thelocking of the mutual engagement between the male and female connectors.

Also, the engaging portions 103 of the flexible arms 102 arerespectively formed in such a manner as to project from the outersurfaces of their associated flexible arms 102 toward the male connectorhousing side, while the projecting lengths thereof increase graduallyfrom the front end side of the male connector housing toward the rearend side thereof. By the way, the present male connector 99 includes inthe width direction thereof two terminal storage chambers 99 a which arecapable of storing female-type terminals therein.

On the other hand, the other connector, namely, the female connector 100comprises a pair of arm guide surfaces 104 respectively which arecapable of flexing their associated flexible arm 102 until the mutualengagement length between the male and female connectors reaches apreset length. The arm guide surfaces 104 respectively include securingmeans 105 which, when the connector mutual engagement length reaches thepreset length, can secure their associated engaging portions 103 tothereby lock the mutually engaged condition between the two connectors.The present securing means 105 respectively consist of stepped portionswhich are formed in the rear end portions of their associated arm guidesurfaces 104 in such a manner that their associated engaging portions103 can be engaged with the securing means 105.

As shown in FIG. 19, the two arm guide surfaces 104 are respectivelyformed on the housing side surfaces of the female connector 100 in sucha manner that, when the male and female connectors 99 and 100 areoperated for their mutual engagement, the engaging portions 103 of thetwo flexible arms 102 can be contacted with the arm guide surfaces 104.As the mutual engagement between the male and female connectorsadvances, the arm guide surfaces 104 gradually flex their respectiveflexible arms 102 inwardly.

When the engaging portions 103 of the flexible arms 102 are respectivelyengaged with the securing means 105 of the female connector 100, theflexible arms 102 are returned from their flexed conditions back totheir original conditions. If the engaging portions 103 are engaged withsecuring means 105, then the engaging surfaces thereof prevent the maleand female connectors from moving in their mutually removing directionsbecause the engaging surfaces intersect at right angles to the connectorengaging direction, so that the mutually engaged condition between themale and female connectors can be locked.

Now, in the connector lock mechanism 98 according to the presentembodiment, the pair of flexible arms 102, 102 and the pair of arm guidesurfaces 104, 104 cooperate together in forming a connector removingmechanism 107. That is, the present connector removing mechanism 107 iscomposed of the pair of flexible arms 102, 102 which are formedintegrally with the male connector 99 and are used as flexible elasticpieces, and the pair of arm guide surfaces 104, 104 which are formedintegrally with the female connector 100 and are used as push-out guidesurfaces.

The arm guide surfaces 104 serving as the push-out guide surfaces, whenthe male and female connectors are engaged with each other, elasticallydeform their respective flexible arms 102 serving as the flexibleelastic pieces to thereby generate a push-out force which acts on themale and female connectors in a direction where they are separated orremoved from their mutually engaged condition.

In more detail, the elasticity of the pair of flexible arms 102 and theinclination angles of the pair of arm guide surfaces 104 are set suchthat the push-out force to be generated by the connector removingmechanism 107 according to the present embodiment is larger than themutual contact resistance caused by and between male- and female-typeterminals respectively stored within the two connectors.

Also, on the respective inner side surfaces of the pair of flexible arms102 and 102, there are provided wrong operation preventive pieces 109 insuch a manner that they are formed integrally with their associatedflexible arms 102. As shown in FIGS. 17 and 18, if an operator tries toengage the male and female connectors with each other while the flexiblearms 102 are flexed in the locking removed condition, then the wrongoperation preventive pieces 109 interfere with an obstacle plates 110which is disposed within the housing of the female connector 100,thereby preventing the male and female connectors from being engagedwith each other. As shown in FIG. 16, the obstacle plate 110 is arrangedon the upper wall of the female connector housing in parallel theretothrough a support wall 111 which hangs down from the upper wall portionof the housing of the female connector 100.

As shown in FIGS. 17 and 18, the rear end face 110 a of the obstacleplate 110 and the rear end faces 109 a of the wrong operation preventivepieces 109 are respectively chamfered into smoothly curved shapes. Thatis, if the two flexible arms 102 and 102 are flexed from their lockedconditions shown in FIG. 19 into their locking removed conditions tothereby energize the male and female connectors in their mutuallyremoving directions, then the respective curved surfaces of the wrongoperation preventive pieces 109 and obstacle plate 110 are contactedwith each other, so that the wrong operation preventive pieces 109 areallowed to slide into below the obstacle plate 110; that is, themovement of the male and female connectors in their mutually removingdirections is not prevented by the obstacle plate 110.

As described above, in the connector lock mechanism 98 according to thepresent embodiment, when the set of male and female connectors 99 and100 are operated for their mutual engagement, the connector removingmechanism 107 applies to the male and female connectors 99 and 100 thepush-out force which pushes them in their mutually removing directions.Since the push-out force to be generated by the connector removingmechanism 107 is set larger than the mutual contact resistance betweenthe male-type and female-type terminals which are respectively storedwithin the male and female connectors, when the male and femaleconnectors are partially engaged with each other, the male and femaleconnectors are pushed back in their mutually removing directions atleast until the mutually connected condition of the male and femaleterminals is removed. Therefore, the present connector lock mechanism 98is surely able to detect the partially engaged condition between themale and female connectors without fail.

Also, the flexible arms 102 serving as the flexible elastic pieces andarm guide surfaces 104 serving as the push-out guide surfaces, whichrespectively cooperate in forming the present connector removingmechanism 107, are respectively provided in their associated connectorsin such a manner that they are formed integrally therewith. Therefore,when compared with the conventional connector removing mechanism whichuses separate parts such as compression springs or the like, the presentconnector removing mechanism 107 can reduce the number of parts requiredin the connectors as well as the number of assembling steps thereof,which in turn makes it possible to reduce the manufacturing coststhereof.

Further, since the wrong operation preventive pieces 109 are formedintegrally with their associated flexible arms 102, even if the mutuallyengaging operation between the male and female connectors is executed inerror in a state where the flexible arms 102 are flexed in the lockingremoved condition, there is surely prevented the possibility that theconnector mutually engaging operation can continue in a state where thepositions of the flexible elastic pieces are deviated from the positionsof the push-out guide surfaces, that is, in a state where the presentconnector removing mechanism 107 cannot operate normally. This canimprove the reliability of the connector removing mechanism 107.

Next, description will be given below in detail of a seventh embodimentof a connector lock mechanism according to the invention with referenceto FIGS. 20 to 23. In particular, FIG. 20 is an exploded perspectiveview of the seventh embodiment of a connector lock mechanism accordingto the invention; FIG. 21 is a longitudinal section view of male andfemale connectors respectively shown in FIG. 20, showing a partiallyengaged condition between them; FIG. 22 is a longitudinal section viewof the male and female connectors shown in FIG. 20, showing a completelyengaged condition between them; and FIG. 23 is an explanatory view ofthe relation between a push-out force to be generated by a connectorremoving mechanism and the length of the mutual engagement between themale and female connectors in the seventh embodiment shown in FIG. 20.

Specifically, a connector lock mechanism 115 according to the presentembodiment relates to a set of male and female connectors 116 and 117.One of the two connectors, namely, the male connector 116 includes apair of flexible arms 119 and 119 which are respectively formed in sucha manner as to extend along a direction thereof (in FIG. 20, in adirection of an arrow H) in which the male connector 116 can be engagedwith the other connector, namely, the female connector 117, while theflexible arms 119 include between them an engaging portion 120 which isformed integrally therewith. Each of the flexible arms 119 is providedon the housing of the male connector 116 in such a manner that it risesup from the front end side of the male connector 116 housing and thenextends toward the rear end side thereof. The free end portions of thetwo flexible arms 119 which are situated in the rear end side of themale connector housing are connected together to thereby form anoperation portion which can be used to remove the locking of the mutualengagement between the male and female connectors. The engaging portion120 of the flexible arms 119 is formed in such a manner as to projectfrom the outer surfaces of the flexible arms 119 toward the maleconnector housing side, while the upwardly projecting length thereofincreases gradually from the front end side of the male connectorhousing toward the rear end side thereof. It is noted that the presentmale connector 116 includes in the width or lateral direction thereoftwo terminal storage chambers 116 a which are capable of storingfemale-type terminals therein.

On the other hand, the other connector, namely, the female connector 117comprises an arm guide surface 121 which is capable of flexing theflexible arms 119 until the mutual engagement length between the maleand female connectors reaches a preset length, while the arm guidesurface 121 includes securing means 105 which, when the connector mutualengagement length reaches the preset length, is capable of securing theengaging portion 120 of the flexible arms 119 to thereby lock themutually engaged condition between the male and female connectors.

As shown in FIG. 21, the arm guide surface 121 is formed on the sidesurface of the housing of the female connector 117 in such a mannerthat, when the male and female connectors 116 and 117 are operated fortheir mutual engagement, the engaging portion 120 of the flexible arms119 contact the arm guide surface 121. In particular, the arm guidesurface 121 is able to flex the flexible arms 119 gradually downwardlyas the mutual engagement between the male and female connectorsadvances. The securing means 123 consists of a rectangular-shapedsecuring hole which is formed in the rear end portion of the arm guidesurface 121 in such a manner that the engaging portion 120 can beengaged with the securing means 123. The female connector 117 stores andholds therein two male-type terminals which correspond to thefemale-type terminals stored within the male connector 116.

As shown in FIG. 22, when the engaging portion 120 of the flexible arms119 is engaged with the securing means 123 of the female connector 117,the flexible arms 119 are returned from their flexed conditions back totheir original conditions. At this time, since the engaging surfacesthereof extend at right angles to the engaging direction of the male andfemale connectors, they prevent the male and female connectors frommoving in their mutually removing directions, so that the mutuallyengaged condition between the male and female connectors can be locked.

In the connector lock mechanism 115 according to the present embodiment,not only the pair of flexible arms 119 including the engaging portion120 between them and the pair of arm guide surface 121 function as afirst connector removing mechanism 125, but also the pair of flexiblearms 119 and a pair of push-out guide surfaces 126 and 126 respectivelyformed in the two inner surfaces of the female connector 117 function asa second connector removing mechanism 127.

That is, the first connector removing mechanism 125 is composed of thepair of flexible arms 119, 119 formed integrally with the male connector116 and serving as flexible elastic pieces, and the pair of arm guidesurfaces 121 formed integrally with the female connector 117 and servingas push-out guide surfaces. The arm guide surfaces 121 functioning asthe push-out guide surfaces, when the male and female connector areoperated for their mutual engagement, can deform elastically theflexible arms 119 serving as the flexible elastic pieces downwardlythrough the engaging portion 120 thereof to thereby generate a push-outforce which removes the mutually engaged condition between the male andfemale connectors.

Also, the second connector removing mechanism 127 is structured suchthat, when the male and female connector are operated for their mutualengagement, two push-out projections 129 respectively provided on therespective outer side surfaces of the two flexible arms 119 arecontacted with their associated push-out guide surfaces 126 to therebyelastically deform the flexible arms 119 inwardly. The elasticdeformation of the flexible arms 119 generates the push-out force whichremoves the mutually engaged condition between the male and femaleconnectors. Therefore, the total of the push-out force to be generatedby the first connector removing mechanism 125 and the push-out force tobe generated by the second connector removing mechanism 127 provides theactually obtainable push-out force.

In the connector removing mechanisms 125 and 127 according to thepresent embodiment, the elasticity of the pair of flexible arms 119, 119when they are flexed and the inclination angles of the arm guidesurfaces 121 and push-out guide surfaces 126 are set in such a mannerthat the total of the push-out force to be generated by the firstconnector removing mechanism 125 and the push-out force to be generatedby the second connector removing mechanism 127 is larger than the mutualcontact resistance caused by and between male- and female-type terminalsrespectively held within their associated connectors.

As described above, in the connector lock mechanism 115 according to thepresent embodiment, when the set of male and female connectors 116 and117 are operated for their mutual engagement, the first and secondconnector removing mechanism 125 and 127 apply to the male and femaleconnectors 116 and 117 the push-out force which pushes them in theirmutually removing directions. Since the push-out force to be generatedby the connector removing mechanisms 125 and 127 is set larger than themutual contact resistance caused by and between the male-type andfemale-type terminals which are respectively stored within the twoconnectors, if the male and female connectors are partially engagedtogether, then the male and female connectors are pushed back in theirmutually removing directions at least until the mutually connectedcondition of the male and female terminals is removed.

Therefore, the present connector lock mechanism 115 is surely able todetect the partially engaged condition between the male and femaleconnectors without fail.

Also, the flexible elastic pieces and push-out guide surfaces, whichrespectively cooperate in forming the present connector removingmechanisms 125 and 127, are respectively provided in their associatedconnectors in such a manner that they are formed integrally therewith.Therefore, when compared with the conventional connector removingmechanism which uses separate parts such as compression springs or thelike, the present connector removing mechanism 125 and 127 can reducethe number of parts required in the connectors as well as the number ofassembling steps thereof, which in turn makes it possible to reduce themanufacturing costs thereof.

Further, since the flexible elastic pieces and push-out guide surfacesrespectively cooperating in forming the present connector removingmechanisms are provided in two or more sets, for example, if therespective sets of flexible elastic pieces and push-out guide surfacesare shifted in the operation timings from one another, the push-outforce to be generated by the present connector removing mechanisms canbe made to vary. Also, if the two or more sets of flexible elasticpieces and push-out guide surfaces are operated simultaneously, then alarge push-out force can be obtained easily and, therefore, even if thenumber of terminals to be stored within the respective connectors islarge, the present connector removing mechanisms are surely able toprovide a necessary and sufficient push-out force.

It is noted that the push-out force that can be obtained when theoperation timings of the first and second connector removing mechanism125 and 127 are shifted from each other provides such a characteristicline F3 as shown in FIG. 23.

Next, description will be given below in detail of an eighth embodimentof a connector lock mechanism according to the invention with referenceto FIGS. 24 to 27. In particular, FIG. 24 is an exploded perspectiveview of the eighth embodiment of a connector lock mechanism according tothe invention; FIG. 25 is a longitudinal section view of male and femaleconnectors respectively shown in FIG. 24, showing a partially engagedcondition between them; FIG. 26 is a longitudinal section view of themale and female connectors shown in FIG. 24, showing a completelyengaged condition between them; and FIG. 27 is an explanatory view ofthe relation between a push-out force to be generated by a connectorremoving mechanism shown in FIG. 24 and the length of the mutualengagement between the male and female connectors.

Specifically, a connector lock mechanism 130 according to the presentembodiment comprises a set of male and female connectors 131 and 132.One of the two connectors, namely, the male connector 131 includes apair of flexible arms 119 and 119 which are respectively formed in sucha manner as to extend along a direction thereof (in FIG. 24, in adirection of an arrow I) in which the male connector 131 can be engagedwith the other connector, namely, the female connector 132, while thetwo flexible arms 119 include an engaging portion 134 formed integrallytherewith. Each of the flexible arm 119 is provided on the housing ofthe male connector 131 in such a manner that it rises up from the frontend side of the male connector 131 housing and then extends toward therear end side thereof. The respective free end portions of the twoflexible arms 119 which are situated in the rear end side of the maleconnector housing are connected together to thereby form an operationportion which can be used to remove the locking of the mutual engagementbetween the male and female connectors.

Also, the engaging portion 134 is interposed between the flexible arms119 and, as shown in FIGS. 25 and 26, is formed in a curved surface inwhich the upwardly projecting length thereof increases gradually fromthe front end side of the housing of the male connector 131 toward therear end side thereof. The present male connector 131 includes in thewidth direction thereof two terminal storage chambers 131 a which arecapable of storing female-type terminals therein.

On the other hand, the other connector, namely, the female connector 132comprises an arm guide surface 135 which is capable of flexing theflexible arms 119 until the mutual engagement length between the maleand female connectors reaches a preset length. The arm guide surface 135includes securing means 136 which, when the connector mutual engagementlength reaches the preset length, can secure the engaging portion 134 ofthe flexible arms 119 to thereby lock the mutually engaged conditionbetween the male and female connectors 131 and 132.

As shown in FIG. 25, the arm guide surface 135 is formed on the sidesurface of the housing of the female connector 132 in such a mannerthat, when the male and female connectors 131 and 132 are operated fortheir mutual engagement, the engaging portion 134 of the flexible arms119 contact the arm guide surface 135. In particular, the arm guidesurface 135 is structured such that it can flex the flexible arms 119gradually downwardly as the mutual engagement between the male andfemale connectors advances. Also, the securing means 136 consists of astepped portion which is formed in the rear end portion of the arm guidesurface 135 in such a manner that the engaging portion 134 can beengaged with the securing means 136. It is noted that the femaleconnector 132 stores and holds therein two male-type terminals whichcorrespond to the female-type terminals stored within the male connector131.

As shown in FIG. 26, when the engaging portion 134 of the flexible arms119 is engaged with the securing means 136 of the female connector 132,the flexible arms 119 are returned from the flexed conditions back totheir respective original conditions. At this time, because the engagingsurfaces thereof extend at right angles to the connector mutuallyengaging direction, the mutually engaged condition between the male andfemale connectors can be locked positively.

Also, in the connector lock mechanism 130 according to the presentembodiment, not only the pair of flexible arms 119, 119 and the armguide surface 135 function as a first connector removing mechanism 125,but also the pair of flexible arms 119, 119 and a pair of push-out guidesurfaces 139, 139 respectively formed in the two inner surfaces of thefemale connector 132 function as a second connector removing mechanism140.

That is, the first connector removing mechanism 138 is composed of thepair of flexible arms 119, 119 formed integrally with the male connector131 and serving as flexible elastic pieces, and the arm guide surface135 formed integrally with the female connector 132 and serving as apush-out guide surface. And, the arm guide surface 135 functioning asthe push-out guide surface, when the male and female connector areoperated for their mutual engagement, elastically deforms the flexiblearms 119 serving as the flexible elastic pieces downwardly through theengaging portion 134 thereof to thereby generate a push-out force whichremoves the mutually engaged condition between the male and femaleconnectors.

Also, the second connector removing mechanism 140 is structured suchthat, when the male and female connector are operated for their mutualengagement, the push-out guide surfaces 139 are allowed to press againsttwo push-out projections 142, which are respectively provided on andprojected from the respective outer side surfaces of the two flexiblearms 119, inwardly to thereby elastically deform the flexible arms 119inwardly. The elastic deformation of the flexible arms 119 can generatethe push-out force which removes the mutually engaged condition betweenthe male and female connectors 131 and 132.

Therefore, the total of the push-out force to be generated by the firstconnector removing mechanism 138 and the push-out force to be generatedby the second connector removing mechanism 140 provides the actuallyobtainable push-out force.

Also, in the connector removing mechanisms 138 and 140 according to thepresent embodiment, the elasticity of the pair of flexible arms 119, 119when they are flexed and the inclination angles of the arm guide surface135 and push-out guide surfaces 139 are set in such a manner that thetotal of the push-out force to be generated by the first connectorremoving mechanism 138 and the push-out force to be generated by thesecond connector removing mechanism 140 is larger than the mutualcontact resistance caused by and between the male- and female-typeterminals respectively held within their associated connectors.

As described above, in the connector lock mechanism 130 according to thepresent embodiment, when the set of male and female connectors 131 and132 are operated for their mutual engagement, the first and secondconnector removing mechanisms 138 and 140 apply to the male and femaleconnectors 131 and 132 the push-out force which pushes them in theirmutually removing directions. Since the push-out force to be generatedby the connector removing mechanisms 138 and 140 is set larger than themutual contact resistance between the male- and female-type terminalswhich are respectively stored within their associated connectors, if themale and female connectors are partially engaged together, then the maleand female connectors 131 and 132 are pushed back in their mutuallyremoving directions at least until the mutually connected condition ofthe male- and female-type terminals is removed. Therefore, the presentconnector lock mechanism 130 is surely able to detect the partiallyengaged condition between the male and female connectors 131 and 132without fail.

Also, the flexible elastic pieces and push-out guide surfaces, whichrespectively cooperate in forming the present connector removingmechanisms 138 and 140, are respectively provided in their associatedconnectors in such a manner that they are formed integrally therewith.Thanks to this, when compared with the conventional connector removingmechanism which uses separate parts such as compression springs or thelike, the present connector removing mechanisms 138 and 140 can reducethe number of parts required in the connectors as well as the number ofassembling steps thereof, which in turn makes it possible to reduce themanufacturing costs thereof.

It is noted that the push-out force that can be obtained when theoperation timings of the first and second connector removing mechanism138 and 140 are shifted from each other provides such a characteristicline F4 as shown in FIG. 27.

As has been described heretofore, according to the invention, there isprovided a connector lock mechanism which comprises a connector removingmechanism. The present connector removing mechanism is composed of aflexible elastic piece formed integrally with one connector, and apush-out guide surface which is formed integrally with the otherconnector and also which, when the two connectors are operated for theirmutual engagement, can deform the flexible elastic piece elastically tothereby generate a push-out force that separates the two connectors fromeach other in their mutually removing directions. And, the elasticity ofthe flexible elastic piece and the inclination angle of the push-outguide surface are set in such a manner that the push-out force to begenerated by the present connector removing mechanism is larger than themutual contact resistance caused by and between male- and female-typeterminals which are respectively held within their associatedconnectors.

Therefore, not only because, when a set of male and female connectorsare operated for their mutual engagement, the present connector removingmechanism applies to the male and female connectors the push-out forcewhich acts on the male and female connectors in directions where theyare separated from each other, but also because the push-out force to begenerated by the present connector removing mechanism is set larger thanthe mutual contact resistance caused by and between male- andfemale-type terminals within their associated connectors, if the maleand female connectors are partially engaged, then the male and femaleconnectors are pushed back in their mutually separating or removingdirections at least until the connected condition between the male- andfemale-type terminals is removed. This makes it possible to surelydetect the partially engaged condition between the male and femaleconnectors without fail.

Also, since the flexible piece and push-out guide surface cooperatingtogether in forming the present connector removing mechanism arerespectively formed integrally with their associated connectors, whencompared with the conventional connector removing mechanism which usesseparate parts such as compression springs, the present connectorremoving mechanism can reduce the number of parts required in theconnectors as well as the number of assembling steps thereof, which inturn makes it possible to reduce the manufacturing costs thereof.

Also, in the above-mentioned connector lock mechanism, preferably, theflexible arm may also serve as the flexible elastic piece and the armguide surface may also serve as the push-out guide surface. That is, inthe present preferred embodiment, the respective connectors can besimplified in structure, which in turn can enhance the moldability ofthe connectors as well as the yield of the products.

Further, in the above-mentioned connector lock mechanism, preferably,within the range of the above-mentioned mutual engagement between themale and female connectors, the inclination angle of the push-out guidesurface may be changed properly in the intermediate portion thereof insuch a manner that a greater push-out force can be generated in therange of the mutual connection between the above-mentioned male- andfemale-type terminals than in the unconnected condition between themale- and female-type terminals. That is, in the thus structuredpreferred embodiment, in the unconnected condition between the male- andfemale-type terminals in which the mutual resistance between the male-and female-type terminals does not act, the push-out force to begenerated by the connector removing mechanism can be controlled to aminimum, which makes it possible to save an operation force necessaryfor mutual engagement between the male and female connectors. Therefore,the operation for mutual engagement between the male and femaleconnectors can be improved in efficiency.

Still further, in the above-mentioned connector lock mechanism,preferably, the flexible elastic piece may be formed integrally with theflexible arm, and a wrong operation preventive piece, which is used toprevent the male and female connectors from being engaged with eachother while the flexible arm is flexed in its locking removed condition,may be formed integrally with the flexible arm. That is, in the presentpreferred embodiment, even if the mutual engagement between the male andfemale connectors is executed in error while the flexible arm is flexedin its locking removed condition, the connector removing mechanism isprevented from operating normally in a condition where the position ofthe flexible elastic piece is shifted from the position of the push-outguide surface. Therefore, the mutual engagement between the male andfemale connectors due to the inadvertent flexing of the flexible arm canbe prevented, thereby being able to enhance the reliability of theconnector removing mechanism.

Yet further, in the above-mentioned connector lock mechanism,preferably, the above-mentioned flexible elastic piece and push-outguide surface may be provided in two or more sets. That is, in thepresent preferred embodiment, if the operation timings of the respectivesets of flexible elastic pieces and push-out guide surfaces are shiftedfrom one another, then the push-out force to be generated by theconnector removing mechanism can be made to vary.

Also, if the two or more sets of flexible elastic pieces and push-outguide surfaces are operated simultaneously, then a large push-out forcecan be provided easily. Therefore, even if the number of terminals to bestored within the respective connectors is large, there can be obtaineda necessary and sufficient push-out force.

Moreover, in the above-mentioned connector lock mechanism, preferably,while the flexible arm is held in its flexed condition, a push-out forceacting on the male and female connectors in their mutually removingdirections may be always generated due to the flexed condition of theflexible elastic piece; and, if the male and female connectors areengaged with each other completely, then the flexed conditions of theflexible arm and flexible elastic piece may be removed, thereby beingable to remove the push-out force acting on the male and femaleconnectors in their mutually removing directions. Therefore, when themale and female connectors are completely engaged with each other, theflexible elastic piece, together with the flexible arm, can be returnedto its original condition, which makes it possible to prevent thefatigue of the flexible elastic piece caused by the long flexedcondition thereof.

What is claimed is:
 1. A connector lock mechanism for locking theconnected condition of a set of male and female connectors to be engagedwith each other, the connector lock mechanism comprising: a flexible armdisposed on one of the male and female connectors and extending in acantilevered manner along a direction in which one of the male andfemale connectors can be engaged with the other one of the male andfemale connectors, said arm including a base end which is directlyconnected to the one of the male and female connectors; an engagingportion disposed on the flexible arm; an arm guide surface disposed onthe other connector one of the male and female connectors for flexingthe flexible arm until a connector mutual engagement length between thetwo connectors reaches a preset length; a securing member disposed onthe other connector, said securing member securing the engaging portionof the flexible arm to thereby prevent the two connectors from beingremoved from each other when the connector mutual engagement lengthreaches the preset length; and a connector removing mechanism includingsaid flexible arm, and a push-out guide surface which is formedintegrally with said other connector and also which, when said twoconnectors are operated for their mutual engagement, deforms saidflexible arm elastically to thereby generate a push-out force separatingsaid two connectors from each other in mutually removing directions,wherein the elasticity of said flexible arm and an inclination angle ofsaid push-out guide surface are set such that said push-out forcegenerated by said connector removing mechanism is greater than contactresistance caused by mutual connection between male- and female-typeterminals respectively held within their associated connectors.
 2. Theconnector lock mechanism of claim 1, wherein said arm guide surfaceserves as said push-out guide surface.
 3. The connector lock mechanismof claim 1, wherein, in the range of the mutual engagement between saidtwo connectors, the angle of said push-out guide surface is changed inthe intermediate portion thereof so that a greater push-out force can begenerated in the mutually connected range of said male- and female-typeterminals than in the mutually unconnected range of said male- andfemale-type terminals.
 4. The connector lock mechanism of claim 1,wherein said connector lock mechanism includes two of said flexible armsand said push-out guide surfaces, respectively.
 5. The connector lockmechanism of claim 1, wherein, while said flexible arm is held in aflexed condition, the flexed condition of said flexible arm generatessaid push-out force acting said two connectors in their mutuallyremoving directions and, if said two connectors are completely engagedwith each other, the flexed condition of said flexible arm is removed,thereby removing said push-out force acting in said connectors mutuallyremoving directions.